The present invention refers to metering aerosol dispensing devices, and in particular to an actuating device for meters which can be easily used in metering aerosol dispensing devices.
There are known various metering aerosol dispensing devices for inhalation purposes which dispense an amount of medicament or drug of an exact dose in the form of a mist or an aerosol for instance for the treatment of respiratory tract diseases. Here, above all, the reliable metering of the dispensed medicament is important so that a specific therapeutical effect for the patient can be achieved. Such metering aerosol devices are for instance the generally known MDI (metered dose inhalers) which normally have a housing, a container for accommodating a liquid or powdery medicament, a suitably designed nozzle for atomizing and distributing the medicament, and a mouthpiece via which the generated medicament-containing aerosol is inhaled. In case of propellant aerosols, the actuation of the metering aerosol devices is effected for instance in such a way that the medicament container is displaced linearly with respect to the nozzle arranged in the housing, whereby a defined amount of the atomization material is released. A metering aerosol device of said kind is described for example in EP 0 254 391.
Metering aerosol dispensing devices usually are designed for multiple dosages. In this connection it is desirable that the number of the dispensed doses, in other words of the dispensed spraying puffs, or of the still available spraying puffs are indicated to the user in order to guarantee that the patient is informed at an early point of time of the fact that the medicament is consumed. Thereby it is avoided that a patient carries with him or her an already almost empty metering aerosol dispensing device for instance as a prophylaxis of an acute asthmatic attack.
Therefore controlled-dosage atomizers or controlled-dosage inhalers have been provided with different meters or counters. For instance in EP 0 254 391 there is described an inhaler with a flat meter which is formed on the side of an aerosol dispenser facing the patient. From EP 0 505 321 there is known a reusable inhaler with a resettable meter which is incremented when the first relative position of storage chamber and metering pin is reached. The meter disclosed in GB 1 317 315 has a plurality of annular elements which cooperate mechanically in order to indicate at an indicator ring the dosages still available. Further medicament dispensers with a mechanical meter are disclosed for instance in FR 2.022.212, WO 86/02275 and WO 93/24167.
The known solutions for metering devices, however, have either a complex, unmanageable structure or require rather considerable modifications of an already existing metering aerosol dispensing device. But such a modification of an already existing metering aerosol dispensing device is disadvantageous in that afterwards said device has once again to be subjected to an official approval procedure and the tests involved therewith regarding the medical applicability. This, however, usually is a tedious and expensive process and therefore is undesirable.
Consequently, proceeding from prior art, the object of the present invention is to develop for a metering aerosol device an actuating device for meters with small dimensions which can be used with different metering aerosol dispensing devices for counting the dosages without substantial modifications having to be carried out at the metering aerosol devices.
Said object is solved according to the invention by a metering aerosol dispensing device with an aerosol container, a nozzle arranged in a nozzle body, whereby an aerosol is dispensed via said nozzle when the aerosol container is displaced with respect to the nozzle body when the metering aerosol dispensing device is actuated, a meter for counting the actuations of the metering aerosol dispensing device, and an actuating device for shifting onward the meter when the metering aerosol dispensing device is actuated, wherein the actuating device comprises two sleeves displaceable, with respect to each other which, in the interior, accommodate the nozzle body of the metering aerosol dispensing device such that the nozzle is released in order to produce an aerosol in an unrestricted manner, wherein the sleeves are displaceable linearly with respect to each other and wherein the sleeves are connected with each other via spring elements which move the sleeves back into a starting position.
Advantageously, said spring elements are realized in the form of flat, curved spring elements which are fixed to the outsides of the sleeves or are integrally formed therewith.
In order to avoid a jamming of the sleeves, there are provided guiding elements at the sleeves of the actuating device which ensure a straight-lined displacement of both sleeves against each other. Alternatively, the spring elements can be designed such that they guarantee a linear displacement of both sleeves against each other.
For shifting or moving onward the meter, the actuating device comprises an actuating arm which acts upon the meter.
In order to realize as small a meter as possible, the meter consists of several disk units arranged in parallel, wherein a first disk unit has an external toothing which cooperates with the actuating device, in particular with the actuating arm.
In order to form a unit of the meter and the actuating device, the actuating device has an opening in which a bearing pin of the meter is fixed for holding the meter at the actuating device.
In order to ensure that the aerosol generation and spreading is not influenced, the actuating device, in particular the lower part thereof, is provided with a recess or an opening through which the nozzle is released.